Except for grasshoppers, reported metabolic rate measurements are averages of all available no-beam CO2 recordings
for each of the four species. For grasshoppers, metabolic rates were
not averaged due to the wide mass distribution. Conversion from CO2 output to metabolic rate assumed an energy equivalence of 20.1, 24.5, 27.6 and 21.2 J/ml of CO2 for
grasshoppers [37], beetles [38], ants [39], and fruit flies [40].
Except for grasshoppers and ant abdomen, the beam was larger than the
part of the animal being irradiated. Under nominal beam intensities,
the absorbed power due to the x-ray irradiation was less than 20% of
the unirradiated metabolic rate. Values are mean ± SD.